The present invention relates to the process and catalyst for use therein for the selective removal of acetylenic compounds from gaseous streams. The process and catalyst of this invention are particularly useful for the reduction of acetylenic compound impurities from gaseous streams of organic compounds.
Terms "acetylenes" or "acetylenic compounds" are used to denote acetylene, vinyl acetylene, methyl acetylene, ethyl acetylene and the like. Such compounds are often found as impurities in various organic product streams. For example, the oxidative or non-oxidative dehydrogenation of C.sub.4 -C.sub.8 hydrocarbons having at least one ##STR1## grouping to produce the corresponding ethylenically unsaturated hydrocarbons produces small amounts of acetylenes. In many utilizations of the ethylenically unsaturated hydrocarbons, e.g., (butadiene) in the production of styrene-butadiene rubber, only small amounts, generally less than 1000 ppm acetylenes are acceptable in the butadiene. Similarly, in the production of olefinic hydrocarbons by the cracking of hydrocarbon feed streams, certain quantities of acetylenes are produced. Some ethylene recovery processes, for example, the cuprous salt method, necessitate that the acetylenes be first removed, since acetylene reacts with the cuprous ions to form an explosive compound. Furthermore, ethylene utilized for the purpose of polymerization requires an almost total removal of acetylenes.
Thus, a great effort has been expended to develop methods for removing acetylenes from organic streams, particularly C.sub.2 -C.sub.8 paraffinic and olefinic hydrocarbons. Two approaches have been employed (1) physical, involving distillations, extractions, extractive distillation and various combinations of physical processes and (2) catalytic. Two catalytic approaches are shown in U.S. Pat. Nos. 3,476,824 and 3,728,412.